Spinpolarisierte Photoemission an Pt(111)

Oepen, H. P.

Book/Report

FZJ-2018-02478

Spinpolarisierte Photoemission an Pt(111)

Oepen, H. P. (Corresponding author)FZJ*

1985
Kernforschungsanlage Jülich, Verlag Jülich

Jülich : Kernforschungsanlage Jülich, Verlag, Berichte der Kernforschungsanlage Jülich 1970, 83 p. (1985)

Please use a persistent id in citations: http://hdl.handle.net/2128/18160

Report No.: Juel-1970

Abstract: We report on a new kind of photoelectron spectroscopy : the spin- and momentum-resolved photoemission from nonmagnetic solids using circularly polarizedsynchrotron radiation. Some aspects of the possibility of this new technique are demonstrated in photoemission from Pt(111). In normal emission the sign of the spinpolarization vector, which is oriented along the surface normal, allows to determine double group symmetries of the relativistic band structure along the $\Lambda$-direction of platinum. Moreover it is shown, that the spinpolarized photoelectron spectroscopy is suitable for the investigation of critical points, like bandcrossing and -anticrossing, of bandstructures along high symmetry directions. For emission in a mirror plane of the crystal the orientation of the polarizationvector is determined. It is demonstrated that direct interband transitions cause polarization vectors lying in the mirror plane. In contrast to normal emission, however, there does not exist any quantization axis for the spinpolarization vector to be aligned with. The determination of the polarization vector includes a strong progress of this technique over common photoelectron spectroscopy investigations. The orientation is related to relative phases and magnitudes of distinct matrix elements inthe optical excitation process. In case of mirror emission it will allow to derive precise information on the hybridization of electronic states due to spin-orbit interactions. For quantitative results the relativistic scattering formalism has to be applied to the photoemission process. The influence of the transmission process in photoemission is shown explicit. Intensity asymmetries, that means different energy distributions for the excitation with light of opposite helicity, are measured for thefirst time. These asymmetries are caused by spin-dependent scattering in the surface layers during transmission into vacuum.

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